Riders Of Vision

General => TechTalk => Topic started by: Prophet Of Doom on July 25, 2013, 07:51:59 AM

Title: Big-Arse Brakes Mod
Post by: Prophet Of Doom on July 25, 2013, 07:51:59 AM
In my parts box I have a pair of shiny gold NOS Brembo 4 pot calipers (Ducati ST2, ST4), and a pair of R1 rotors.  The pic with the Tokico calipers are my rotors, but the owner wouldn't sell me the calipers :-(

The rotors just bolt on, so no issues there,  but I need to make adapters for the calipers.  These aren't floating calipers so will need to quite exact, and I'd rather not kill myself first time out.  It will also need to be certified by a government official, so needs to be done competently.

So who here has done this or something similar and wants to share their hints and tips?  There must be heaps of visionaries who would like to sex up their bike a bit.

What sort of material is best to use?
How to calculate perfect drill locations?
How to space correctly?
Safety considerations ?
etc etc


Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on July 25, 2013, 11:48:56 AM
This is a great topic which should prompt some good discussions and maybe even some debate.  ;) I'll relate my experiences (over several entries) although some of it will only apply to using like components. Depending on the components used, the process may become more involved and possibly require some machining? In my case only a drill press and band saw was used although the band saw was a luxury that may be replaced with more manual cutting processes. I suppose even the drilling could be done by hand held drills but I felt more comfortable with the relative precision of a press.

In my parts box I have a pair of shiny gold NOS Brembo 4 pot calipers (Ducati ST2, ST4), and a pair of R1 rotors.  The rotors just bolt on, so no issues there,  but I need to make adapters for the calipers.  These aren't floating calipers so will need to quite exact I though so too but now think there may be some wiggle room which I'm sure we'll cover later...,  It will also need to be certified by a government official, so needs to be done competently.  hmmm, how picky are they!?  :o  :D

What sort of material is best to use? steel is heavy but stronger than aluminum and not as sexy. If you can afford even more exotic materials good for you!
How to calculate perfect drill locations? definitely was one of my concerns too
How to space correctly? yup, another good one. Ideally, find the clearance of rotor to caliper carrier on the component's OEM setup. I used components another member used so this work had been done for me.  :)
Safety considerations ? still in the testing stages with just under 200 miles on the setup so I'll keep you posted but so far so good.  :)
Title: Re: Big-Arse Brakes Mod
Post by: treedragon on July 25, 2013, 04:33:10 PM
Government official???  I just put mine on and it was accepted as normal at the next WOF  ;D
.... and of course it was nothing to do with the fact we do WOF checks anyway. These days your regular WOF station hasn't a clue what it should be like anyway.

Best tip I can give is to connect your calipers to master cylinder etc, place them on the rotors on wheel and clamp brake on. This will hold them in their natural position relative to everything else and make measuring a lot easier.

I used thick aluminium plate (because it was there) and milled out the inner side to suit the various mount points.

 
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on July 25, 2013, 07:35:37 PM
I've noticed the 4 pot caliper adapter plates are mounted to the front of the fork leg caliper mounting bosses and the caliper attaches behind the adapter. Treedragon's FZR units, HarryTakeuchi's Brembos and the pic roro posted of TL1000 Tokico calipers are all like this. What I can't see from the picture angle is if the adapter plate is stepped or relieved in the back where the caliper attaches to facilitate the correct "offset" or rotor clearance? Treedragon, when you say you "milled out the inner side..." is this what you mean?

As far as clamping the caliper to the rotor via hydraulics to measure the offset or plate thickness requirement, aren't you relying on the pistons all starting at the same place and extending equally front and back when extended? Would it be wise to visually check that nothing interferes with the rotor and the wheel "spokes" when the caliper is hydraulically clamped to the rotor prior to committing to the adapter plate measurements?

What I mean is, imagine the caliper mounted on an adapter plate and it just so happens the pistons are all extended equally. Actually I guess this would be the goal provide it coincided with all clearance requirements. Anywho, now imagine you modified the plate by removing some material just where the caliper mounts and reinstalled the caliper effectively changing the caliper's offset relative to the rotor. Pumping the brake lever advances the caliper pistons but now on one side of the rotor they are extended further than the pistons on the other side. Lets assume there is still proper rotor clearance but that's not necessary for this exercise. In both scenarios the adapter plate has defined where the pistons end up - not the whims of hydraulics and path of least resistance. My point is, prior to creating the adapter, simply pumping the lever to clamp the caliper to the rotor may not guarantee the pistons extend equally front and back and/or proper clearance has been established. Yes? No?
Title: Re: Big-Arse Brakes Mod
Post by: jefferson on July 25, 2013, 11:13:49 PM
The pistons don't really have to be equally extended for everything to work ok, but then I don't think that was exactly your question. The main thing is to get the disc in the center of the slot in the caliper and to get the caliper raised off the outer edge of the disc the proper distance. A friend of mine was doing some very intricate mounts for the calipers on a Squalo (beautiful bike) and he used a piece of wire layed on the edge of the disc to get the proper spacing to the caliper. Very easy and it worked perfectly.
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on July 26, 2013, 08:58:31 AM
Yes, my point exactly - holding the caliper in position using brake pressure is handy during fitment but simply pumping the brake lever doesn't necessarily guarantee the caliper is centered left to right correctly or is repeatable. The "up and down position" if you will, is yet another factor.  I laid the brake pads on my "new" used rotor (FJR1300 in my case) leaving a margin of rotor showing and otherwise placing them where they looked right. I then took the highly scientific approach of tracing their outline onto the rotor with a Sharpie marker. After reassembling the pads into the Suzuki SV650 caliper I positioned the caliper onto the rotor using the pad outline as a guide.

I wanted to find a way to quickly locate the caliper into position without using the marker outline much like your tip of using a length of wire as a shim. There are pad guide pins at either end of the SV caliper. I found that placing a sleeve from proper sized (wall thickness) tubing over the exposed portion of pin spaced the caliper just right. These sleeves were cut to length then slit along their length to facilitate slipping over the pins. This way, every time I removed/replaced the caliper during fitting it was a simple matter of resting the "padded" caliper pins on the edge of the rotor and the placement was perfect making the marker guides unnecessary from that point on.

Only then did I bolt the rotor to the wheel, install the wheel and introduce the caliper into the system and bleed the air to make it functional. Obviously I had gone through the caliper prior to ensure it was serviceable.  :)

Getting back to caliper position left to right, in my case someone else already did the work. Jasonm used SV calipers (floating 2 pot) on his twin disk setup although with R1 rotors. His adapter plate is 1/4" thick steel bolted behind the leg bosses with the caliper bolted behind it utilizing the caliper's threaded mounting holes. It just so happens this places the caliper correctly so no spacing or milling was needed in my case.
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on July 26, 2013, 11:58:30 PM
I think I'd like to use alloy rather than steel.  It's easier to work with and for small quantities the cost makes no real difference.   
Treedragon - how thick was your plate?  I have some 6mm 6061, but it looks a bit thin - should I go to 8 or 10mm do you think? and will 6061 be OK ?

Here's a pic of the Brembos tied on with safety wire with the R1 Rotor.  (see pic 1) Pretty happy with the look.  This will enable me to make a rough outline in metal.  I'll make a transfer punch out of the correct sized bolt to mark the hole locations.  I'll use the wire trick for the spacing with some Tig rod I have lying around for the offset from the rotor.

The Brembos have a 7.75mm slot where the 4.75mm rotor goes, and I've found that the wheel is not dead centre - there's a 3mm difference between left and right side from the rotor to the fork leg.  That's wider that the margin of error.  I'll have to pull my wheel off and figure why it's not lining up properly - seems the front axle is poking through too far, but I can't see that there's anything to stop it. (See pic 2)

Once I've sorted the wheel left/right alignment the next question will be the caliper offset - looks to be about 5mm inside of the fork lugs, so I'll need to either build that up with a couple of washers, or mill out the part where it mounts on to the fork and add that to the overall thickness of the plate I use.  I don't have a mill, but may be able to get access to one.  Are washers OK or should I find out about milling?

Title: Re: Big-Arse Brakes Mod
Post by: fret not on July 27, 2013, 12:34:05 AM
Roro, check the wheel alignment before you start changing wheel spacing and stuff like that.  Some bikes have intentionally offset components for alignment and balance.  Just because it looks odd doesn't mean it is.
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on July 27, 2013, 06:46:25 AM
Roro, since my adapter plate goes behind the fork I was limited to nominal 6mm thickness and steel was a better choice. I'd agree alloy would work for yours and seems to be the common material when space permits. The 4 pot caliper's mounting hole location seems to dictate the plate has to go on the outside of the fork bosses. The first pic is an adapter plate (not for a Vision) being made. The material is aluminum and quite thick and ended up going on the outside of the fork.

With your wheel alignment issue can I suggest loosening (or removing) the fork brace, loosening the axle and pinch bolt, then jouncing the suspension a bit. Snug up the axle and jounce some more then snug up the axle pinch bolt and see where the wheel ends up. Leave the fork brace loose during all this.

Since my caliper position (L/R) had been figured out by someone else  :) and the tubing shims placed it where it needed to be up/down, the only thing left was to create the adapter. Jason had suggested using 1/4" acrylic as a template material as it machines easily and is sufficiently robust for the job. I found another good reason to use it although I used some 1/8" I already had.

I printed a picture of the caliper/rotor mock up (second pic) that I merely eye-balled into what seemed like a good position relative e to rotor and caliper. I printed it out at various sizes until the fork boss center to center distance was actual. Then I laid the clear acrylic on the pic and drew with a "Sharpie" the basic adapter plate shape. After cutting the template out it was a just a matter of transferring the hole locations and drilling them. I used the finished template to bolt everything together. It looked good so I transferred everything to the steel plate and finished the part.
Title: Re: Big-Arse Brakes Mod
Post by: jefferson on July 27, 2013, 11:27:18 AM
I am having visions of 35mm forks bent backwards!
Title: Re: Big-Arse Brakes Mod
Post by: QBS on July 27, 2013, 05:39:25 PM
Me too.  However, the small V front tire may not provide enough traction to bend the forks.  That raises the question: Is huge braking power necessary if it can't be be used?  Once the front tire locks up, maximum deceleration has been achieved.  End of story.  Having said that, there is a case to be made for the ability of big brakes to make it easier to modulate ones approach to lock up.  But, that can probably still be achieved with less braking power bolted on.  The benefits of less unsprung weight are also worthy of consideration.  None the less, the enhanced appearance of trick modifications is hard to deny.

Consider that bikes that have this level of braking power from the factory also have more power, bigger front rubber, and stronger forks.  They can therefore use big braking power. 
Title: Re: Big-Arse Brakes Mod
Post by: jefferson on July 27, 2013, 06:16:41 PM
I like having really good brakes. The one thing that really helped me out with the 83 setup I had on the racebike was getting the rotors cryo treated. There was a chicane on the backstraight at Heartland Park that would get the old pulse accelerated at least once every race weekend. I just didn't know if I was going to get slowed down for the corner. After the cryo I never had another issue of doubt. Psychological maybe, but I will take it. Now the guy here in town that did it is out of business.

Jeff
Title: Re: Big-Arse Brakes Mod
Post by: treedragon on July 27, 2013, 09:20:11 PM
A slightly different point of view..........

If you need to stop THAT urgently you haven't been paying attention and likely you don't really care at that point as long as you live  ;D ;D
I KNOW this  ::)

Without a decent master cylinder as well, the full potential will not be there anyway judging from the changeover on my bike that is why I found another master cylinder.
Generally speaking when under full braking the front forks are compressed so that means there is very little fork slider length to bend......

Which reminds me of an early Suzuki GSX something or other I met on the HAAST road when parts were still gravel, his forks were nearly vertical after having hit something, his brakes still worked..............   I do believe he was traveling rather slowly as a result though  ;D  ;D  ;D

 I agree with QBS re bigger brakes maybe being easier to modulate however the original brakes were good at this, you just slammed them on hard and they slooowly and predictably slowed you down and in this case the "paying attention" bit meant allowing enough room ahead.......... ahem ::)
Title: Re: Big-Arse Brakes Mod
Post by: jefferson on July 27, 2013, 10:43:09 PM
The bent forks thing was a joke.

Jeff
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on July 28, 2013, 06:58:56 AM
I assumed you were joking but the takeaway is 2 four pot calipers almost seems like overkill for the smallish V tire's potential. I can say this not from having ridden a V with this setup but rather extrapolating from the significant improvement on mine with only one disk w/2 pot caliper. I can also appreciate the "can't have too much braking available" school of thought though....  :D

To treedragon's comment re the master cylinder, I noticed a diminished initial firmness in the lever after the swap. One reason may be the SV caliper has nearly 25% more piston area than the XZ piston requiring more volume to keep the same initial lever feel?  I'm guessing the area difference between a XZ caliper and a 4 pot caliper may be greater yet. On a related note..... prior to doing the swap I spoke with several people about using a dual disk caliper (larger piston) on my single disk setup. All parties hypothesized there would be less feel/feedback and didn't advise it. Still curious though...  ;)

At 298mm stock RJ rotor vs. 320mm for the R1 and FJR, there is not a dramatic difference. Going from the RK's 267 to 320mm on the other hand, combined with significantly more capable calipers should enable locking the front wheel at any legal speed an easy task.
Title: Re: Big-Arse Brakes Mod
Post by: Rick G on July 28, 2013, 08:35:58 PM
Look up Jasom Morris comments on his modern front brake set up . He listed the whole recipe .
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on July 29, 2013, 07:26:53 AM
Mine is modeled after Jason's work but only some of the particulars apply to what Roro is doing.

Getting back to rotor diameters....  If you have a stock twin disk setup and wanted an economy upgrade I'd suggest using '82 Vision rotors and Tokico calipers similar to what I used. Both are plentiful and can be sourced economically yet will yield an impressive gain in stopping power.  :)
Title: Re: Big-Arse Brakes Mod
Post by: QBS on July 29, 2013, 01:27:55 PM
Could two '82 brake sytems be installed on an '82? 
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on July 29, 2013, 04:08:53 PM
Could two '82 brake sytems be installed on an '82?
The mudguard mounts would be facing the wrong way on the right hand side.
Title: Re: Big-Arse Brakes Mod
Post by: fret not on July 30, 2013, 12:18:39 AM
For the '83 there is a distinct difference between the right and left calipers (mirror ) which would be needed for the '82, plus a suitable lower fork leg (slider).

I think one strong 4 piston caliper and larger disc would provide the stopping power, and larger diameter fork stanchions would help resist twisting under braking with one disc and caliper.  Treedragon is absolutely correct in that you don't need quite such massive stopping power but a lighter front wheel really helps going over rough surfaces while leaning over.  The more time the tire spends in contact with the road surface the more control you have.

In the early 70s I had a Yamaha TR2 production racer which had a front brake (brake only, not rim and tire) that weighed 32 lbs. (14.5kg), and what a marvelous difference when the front wheel was replaced with one that weighed 25 lbs (11.37 kg) INCLUDING the rim and tire.  Going over choppy pavement bent well over was so much smoother and more controllable with the lighter front wheel. 

The technical aspects of handling come down to the sprung vs the unsprung weight of the vehicle.  The heavier the vehicle the heavier your brakes can be, and the lighter the brakes are compared to the rest of the vehicle the better contact the tires will have with the road.
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on July 30, 2013, 06:23:45 AM
Could two '82 brake sytems be installed on an '82?
The short answer is no...  :) Adding to roro and specifically fret nut's comments - if you used the (left) '83 lower leg and caliper on the left side, you'd have to use the smaller diameter '83 rotor on that side as well.  :( So rather than having "two '82 brake systems" you'd have a system consisting of half '82 and half '83 parts.  :D
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on August 05, 2013, 07:20:35 AM
The plate will end up being 7mm at its narrowest point.  Will that be strong enough? I've never done this before so Feedback welcome!!!

I got some 10mm 6061 T6 Plate ($40) from my favourite metal place.
I didn't use acrylic for a template as this is as expensive as aluminium, but I used an acrylic document folder I had lying around and trimmed well enough as a cutting template.  It's just rough - till I get the holes right, and then I'll radius the corners with a belt sander.

The template is transferred to the plate which I'll cut out next week on a bandsaw.  The plan is to get the templates cut out and then make a transfer punch out of a sharpened 12mm bolt to place marks for the holes.  I'll do one at a time so there should be no mistaking where they go.

The caliper is spaced out with a piece of 1.5mm TIG rod duct taped to the rotor

When the whole thing is cut out, I'll mill down the fork leg edge about 3mm to make the caliper align with the rotor - I have some spacing issues I still need to address before I do that.




Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on August 05, 2013, 07:59:08 AM
The plate will end up being 7mm at its narrowest point.  Will that be strong enough? I've never done this before so Feedback welcome!!!  The carrier bracket on the Tokico caliper I used is only 6mm thick although it is steel. If the edges of your pads start to wear you'll know the torsional forces are overwhelming the thin material!  :o  :)

I didn't use acrylic for a template as this is as expensive as aluminium, but I used an acrylic document folder I had lying around and trimmed well enough as a cutting template.  I happened to have some laying around from another project so put it to use. I think treedragon used cardboard so what ever works!  ;)

When the whole thing is cut out, I'll mill down the fork leg edge about 3mm to make the caliper align with the rotor - I have some spacing issues I still need to address before I do that.  Is the milling in lieu of using washers to space it as questioned in an earlier post? What other spacing issues ar you having? Did you figure out the wheel centering?
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on August 05, 2013, 08:30:05 AM
6061 T6 has supposedly better strength and yield than mild steel, though I'm sure there's more to it than that.  I know ali is prone to stress fracturing.

Yes, milling is easy enough at the local high school, so why not, the offset is about 3mm - I think.  I think it will look more pro.  I only get 2 hours a week max on the machines including setup - so I have to plan carefully.  I also have 4 projects on the go at once as machines are shared. 

No I didn't sort the alignment issues out, the fork brace removal/ jiggling made no difference.  It's only a few mm so I'm wondering  if there's some leeway in tolerances that don't matter with floating calipers and so never get noticed.  Plan B is to strip the forks and check the runout of the inners.  My lathe's not big enough so yet another project for my high school shop class.  If I need new inners, I'll get some with an extra 2 inches which will make clip-ons a possibility again.  MikesSX seem to have them at a good price, though some nice Gold Tarozzi inners might be the shit at only EUR250 each.
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on August 05, 2013, 09:34:26 AM
I considered bent stanchions too but didn't want to say it out loud   :(  Maybe it is offset as fret nut mentioned so the left and right adapters will have to be slightly different. If it comes to it, here's another fork tube vendor:
http://www.frankmain.qpg.com/ (http://www.frankmain.qpg.com/)

Quote
6061 T6 has supposedly better strength and yield than mild steel
Stronger by weight or volume of material? If weight, the identical sized steel part would be stronger, right?
Title: Re: Big-Arse Brakes Mod
Post by: sunburnedaz on August 05, 2013, 07:46:14 PM
What year R1 did the rotors come off of?
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on August 05, 2013, 09:07:55 PM
I think they are '03 or earlier 6 bolt design.
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on August 05, 2013, 11:15:16 PM
'98-02 NZ models all had the 6 bolt pattern - then they moved to 5 bolt
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on September 16, 2013, 07:24:10 AM
Seems there is a bit of interest in this - so I'll be fairly detailed.  Skip to the pretty pictures if you like...

So the fork alignment seems to be due to the lower triple.  It's a mm wider than I think it ought to be which translates to 3mm at the bottom.  Because the Vision fork is only really bolted on the left side (the right is floating till the pinch bolt is done up) everything is slightly out of whack.  Not an issue if using floating calipers, but a bit of a deal with the Brembos - I don't want any lateral stresses on the rotors.  I've decided to mill only 2.5mm on each adapter and take up the rest of the space with shims (washers) which will allow the slight off-centredness to be compensated for, but still work if I replace the lower triple down track.

BTW a good way to check for bent stanchions is to lay them together and try to drop a fine feeler gauge between them at the centre, then each end, turn one 1/4 turn and repeat till you have measured each 1/4 with each 1/4.  Any gaps a feeler gauge can enter indicate bendedness (or perhaps lumpy corrosion).

I positioned the rough cut adapter on the fork, and used a sharpened 10mm bolt as a transfer punch to locate the centre of each hole, then drilled out to 3mm, 6mm, 9mm and finally 10mm.  Then I lay the two adapters on top of one another and used the transfer punch to identically match the holes on to the opposite side. (PIC 1)  I then marked where the fork mounts go and milled 2.5mm off to space the caliper inwards.  I just did a straight line - no fancy wobbles. (PIC 2)  Notice that the fork mounts are not evenly spaced out from the fork.  I positioned so that the adapter matches the line of the fork.

There was no way a transfer punch was going to fit into the caliper without hitting the rotor so I cut the 10mm bolt and cut in a screwdriver slot (PIC 3).  Screwed this into the caliper so it was proud, then slid it up to position along the 1.5mm TIG rod taped to the rotor for correct spacing and hit the adapter with a BFH rubber mallet.  You can see the line scribed on the way in and the hole centre (PIC 4)

Drilled out the caliper holes in the same fashion as above and now just have some edges to dress, and radius the corners on the belt sander.

They seem functional enough, though not exactly pretty.  Any opinions on whether I should polish them or powder them black? I'm thinking satin black.

Title: Re: Big-Arse Brakes Mod
Post by: Hellgate on September 16, 2013, 09:45:10 AM
Here's the set up I did on my '82 XV920R. I used FJ600 wheels, EBC rotors and pads, Galfer brakes lines, and FZ1 calipers and MC. My buddy machined the adaptors.

The difference is night and day.



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Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on September 16, 2013, 10:40:01 AM
Hellgate, very nice.  Are they Alloy? How thick? Have they ever been through a safety inspection?
There's a lot more air in those adapters than I would have felt comfortable with, but you have encouraged me to at least think about some speed holes
Title: Re: Big-Arse Brakes Mod
Post by: Hellgate on September 16, 2013, 11:03:20 PM
I don't recall the thickness off the top of my head. I'll measure them tomorrow.

As far as a safety inspection there is no such thing in Oklahoma, even if there was no one would know the difference on a bike that old.

If you consider the direction of the braking forces the cut outs are not an issue.

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

Title: Re: Big-Arse Brakes Mod
Post by: Hellgate on September 17, 2013, 03:15:43 PM
15.5mm thickness.



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Title: Re: Big-Arse Brakes Mod
Post by: charlie h. on September 17, 2013, 05:53:31 PM
The braking thread is piquing my interest, as I have 2 1982 XZ550RJ Visions, also a 1981 XV920RH, and a Vintage roadrace bike, 1975 RD350 with a 1982 XZ550RJ Vision front fork and front wheel, mounted in an XS650 tripletree modded to fit the shorter steering neck of the RD350. I have been checking brake rotor sizes lately, the RJ Vision rotor is 298mm OD, which is the same size as the 98-02 R1 rotors, but the r1's are drilled for better braking. I am interested in fitting either an R1 or R6 single rotor of the same size (298mm) to the front forks/wheel  of the racebike, and then see if i need a better caliper. I am using an FJ1300 Master cylinder with the rd350 and the Vision stock caliper and rotor, so I have plenty of Master cyl. and at Beaver Run (PITT) I has an SV650 about crawl up my butt on the braking into the last hairpin curve. He mentioned the surprise that the RD350 could brake that well. So I am going to find an R1 (98-02) rotor and replace the non drilled stock Vision rotor, and check out the difference. Oh, by the way, I used a XS400 Seca rear wheel on the RD350 to match the Vision front wheel, as it is chain drive, and also have a XS650 swingarm which adds 3" to the wheelbase. All bolts right on, except for the steering stem which I cut down the top bearing step about 5/8" to seat the tapered roller bearings into the top race. What do ya think??
Title: Re: Big-Arse Brakes Mod
Post by: fret not on September 18, 2013, 12:19:44 AM
Drilled discs provide better braking in wet conditions than undrilled ones as they wipe the brake pads clean, and they are a bit lighter which is better for keeping the tire in contact with the road surface.  For significantly better braking get cast iron discs, like Ducati and MotoGuzzi use.  They will rust if allowed but have much better friction characteristics.  Custom brake discs are avaiable for about $100 per made to fit your specs.
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on September 18, 2013, 08:41:29 PM
Prophet - very nice post and love he detail and pics too. Nice creative work-arounds with center punches etc. Can I ask why so many steps when drilling the 10 mm holes? Wouldn't a pilot and then final sizing suffice?

Very odd about the fork/triple clamp alignment issue. I wonder if shimming the stanchions in the top triple would help. I've used strips cut from a soda can for things like this. Maybe a strip placed on the inside section of the top triple to move the centerline of the top of the stanchion out a smidge to match the lower triple clamp width? Just a thought... 

Regarding the color I like the idea of black. Are your sliders black too?


Hellgate - very, very nice and tastefully modified 920 you got there!  :) 
Title: Re: Big-Arse Brakes Mod
Post by: Hellgate on September 18, 2013, 11:57:08 PM
Thanks very much. She's in the process of getting an 1100cc transplant with JE pistons,  Web cams, and porting.  She's also being painted R1 blue.

I tried to use only Yamaha parts and keep a clean OEM look.

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Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on September 21, 2013, 04:03:41 AM
Prophet - very nice post and love he detail and pics too. Nice creative work-arounds with center punches etc. Can I ask why so many steps when drilling the 10 mm holes? Wouldn't a pilot and then final sizing suffice?

Very odd about the fork/triple clamp alignment issue. I wonder if shimming the stanchions in the top triple would help. I've used strips cut from a soda can for things like this. Maybe a strip placed on the inside section of the top triple to move the centerline of the top of the stanchion out a smidge to match the lower triple clamp width? Just a thought... 

Regarding the color I like the idea of black. Are your sliders black too?


Hellgate - very, very nice and tastefully modified 920 you got there!  :)
I guess as long as the previous hole is larger than the next drill's chisel tip you should be generally OK, though I think the more material you take off at a time, the higher the chance of drilling an oversized or out of round hole.  Really they should be drilled then reamed, but I haven't got a set of reamers. 

Yes sliders are black,  but painted and I'm contemplating stripping and powdering.

I'll have to give shimming some thought
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on October 08, 2013, 05:12:12 AM
I removed my forks from the triples to do some shimming and found a tiny (1mm) lump of hard gunk that was throwing the alignment out.  A quick dremmel and everything is in line now.  I re-milled the adapters to take off a final 0.4mm. 

I wanted to use stainless bolts, but finding the right stainless grade for calipers is tricky.   I ended up using M10 grade 12.9 black steel socket cap (all the other bolts on the bike are socket cap, though mostly stainless 316) hacksawed to the right length as it's a strange size and there's no room for overhang.

The calipers sit with about 0.2mm gap either side.  That will change when they are bled, but as they sit they are perfectly centred on the rotor with no rubbing when the wheel is rotated.   It's all getting disassembled when the new over-length fork tubes arrive, so I'll powder these then.

[EDIT] I should add that the standard 3 piece brake lines will not fit.  The 2 line kits look like they will fit for length, but not for orientation of the ends.  I'll try again when it's warmer in the shed than 4 degrees.
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on October 08, 2013, 10:02:52 AM
Very nice work Roro. Looks clean and professionally done. :) Can't wait to see the powder coated finish. Great news about the alignment, glad you got that sorted.  :D  :D
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on October 09, 2013, 12:36:04 AM
Sorry Rigugun, I didn't realise you were incapable of waiting.
Is this better?

I love being able to PC at home.
Title: Re: Big-Arse Brakes Mod
Post by: Re-Vision on October 09, 2013, 12:44:47 AM
You need some gold 83 wheels to match the calipers. Powder coat does look nice.     BDC
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on October 09, 2013, 11:07:00 AM
Sweet! Looks too good to get brake dust on.  ;)
Title: Re: Big-Arse Brakes Mod
Post by: QBS on October 09, 2013, 12:48:26 PM
Outstanding!!  You've done what I could only dream of.  What do you think of the look if the socket heads (but not the washers) were powder coated as well?  I think the gold wheels would be perfect.
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on October 12, 2013, 12:38:41 AM
Thanks QBS, although I used a mill to create the step, it could easily have been done without, and spaced out with washers instead.
Other than that I used no special tools.  It's a job well within the reach of any visionary - just needs a bit of care in aligning everything.

The gold  wheels never made it to this market. 
I suppose I could get a regular pair powdered, but  I have other plans for the wheels.
Title: Re: Big-Arse Brakes Mod
Post by: charlie h. on October 26, 2013, 07:47:12 AM
Hellgate, are those FJ600 wheels 16"? I found a set at my friend's local cycle salvage, and they were 16"... also, do they bolt on without mods to the XV920Rh/RJ forks? Thanks brother, they look killer!
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on November 11, 2013, 05:34:29 AM
Started part 2 of the big-arse brakes mod evening.   Do please chip in with any ideas.
I milled the wheel down so that the outside ring is flush with the centre.  The rotor mount will sit on this.

Title: Re: Big-Arse Brakes Mod
Post by: PwrManDan on November 11, 2013, 06:44:32 AM
you gonna replace the bearings while you are there?  You are far more capable than I am POD, that's all I got LOL.
Title: Re: Big-Arse Brakes Mod
Post by: Rikugun on November 11, 2013, 11:23:21 AM
Do please chip in with any ideas.
I think I see what you did there....  :D And if not your intent, just a happy accident what with all the aluminum chips.  ;)

I didn't know you were making the rear a disk setup too - very cool! How do plan on mounting the rotor? An adaptor plate with the spline hub holes doing double duty?
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on November 11, 2013, 07:49:25 PM
New bearings of course.  They are already in the freezer.

I wasn't going to start this till I had the bike running, but then realised after this month I'd have no milling access till February due to the summer holidays.  Initially I was hoping to have spokey wheels, but now I'm not so sure. 

I thought I'd drill and tap new holes, but clearances are a bit tight, so I'll just use 5 straight through bolts on the original holes.
You can see that the shaft bolts and rotor bolts are well clear of each-other.
Title: Re: Re: Big-Arse Brakes Mod
Post by: Hellgate on November 13, 2013, 01:06:41 PM
Hellgate, are those FJ600 wheels 16"? I found a set at my friend's local cycle salvage, and they were 16"... also, do they bolt on without mods to the XV920Rh/RJ forks? Thanks brother, they look killer!

They are 18" wheels. We had to machine spacers.

I used the rear wheel too and converted from the drum brake to the FJ600 caliper and an FZ6 mc.

EBC rotors all the way around.

Sent from my SAMSUNG-SGH-I747 using Tapatalk

Title: Re: Big-Arse Brakes Mod
Post by: injuhneer on July 13, 2019, 11:30:11 PM
New bearings of course.  They are already in the freezer.

I wasn't going to start this till I had the bike running, but then realised after this month I'd have no milling access till February due to the summer holidays.  Initially I was hoping to have spokey wheels, but now I'm not so sure. 

I thought I'd drill and tap new holes, but clearances are a bit tight, so I'll just use 5 straight through bolts on the original holes.
You can see that the shaft bolts and rotor bolts are well clear of each-other.

How did the finished product look?
Title: Re: Big-Arse Brakes Mod
Post by: Prophet Of Doom on July 14, 2019, 12:19:41 AM
I never did finish that rear wheel.  I put that particular part of the project on the back burner when I found that in New Zealand any mods (other that labelled XZ550 parts) need a compliance certificate at well over $1000.


I'm now rocking stock brakes front and rear, but powder coated, rebuilt (new pistons, seals, pins, MC kit), Brembo ceramic pads, EBC rotors and HEL Stainless Braided lines.  All within the rules and as good as I'll get without signoff from a registered engineer.
Title: Re: Big-Arse Brakes Mod
Post by: injuhneer on July 14, 2019, 12:40:28 AM
I never did finish that rear wheel.  I put that particular part of the project on the back burner when I found that in New Zealand any mods (other that labelled XZ550 parts) need a compliance certificate at well over $1000.


I'm now rocking stock brakes front and rear, but powder coated, rebuilt (new pistons, seals, pins, MC kit), Brembo ceramic pads, EBC rotors and HEL Stainless Braided lines.  All within the rules and as good as I'll get without signoff from a registered engineer.

Hmm. Well if all it needs is a part number... ;-)

I ask because I am working on a similar mod. An aluminum machined plug replaces the drum backing plate. The plug will have the 6 bolt pattern for a rotor. The rest will be bog stock R1 or R6 bits.

I also find that the prices on the XJ900 wheels have escalated a bit.